Resolving dependencies... cabal: Could not resolve dependencies: trying: doc-review-0.7.1 (user goal) trying: base-4.9.0.0/installed-4.9... (dependency of doc-review-0.7.1) next goal: unix (dependency of doc-review-0.7.1) rejecting: unix-2.7.2.0/installed-2.7..., unix-2.7.2.0, unix-2.7.1.0, unix-2.7.0.1, unix-2.7.0.0, unix-2.6.0.1, unix-2.6.0.0, unix-2.5.1.1, unix-2.5.1.0, unix-2.5.0.0 (conflict: doc-review => unix<2.5) rejecting: unix-2.4.2.0, unix-2.4.1.0 (conflict: base==4.9.0.0/installed-4.9..., unix => base>=4.2 && <4.4) rejecting: unix-2.4.0.2, unix-2.4.0.1 (conflict: base==4.9.0.0/installed-4.9..., unix => base>=4.2 && <4.3) rejecting: unix-2.4.0.0 (conflict: base==4.9.0.0/installed-4.9..., unix => base>=4.1 && <4.3) rejecting: unix-2.3.2.0, unix-2.3.1.0, unix-2.3.0.0, unix-2.2.0.0, unix-2.0 (conflict: base==4.9.0.0/installed-4.9..., unix => base<4.3) Dependency tree exhaustively searched.